Insulated solution injector, system including the same, and method of injecting using the same

ABSTRACT

An insulated solution injector may include an outer tube and an inner tube arranged within the outer tube. The outer tube and the inner tube may define an annular space therebetween, and the inner tube may define a solution space within. The annular space may be configured so as to insulate the solution within the solution space. As a result, the solution may be kept to a temperature below its decomposition temperature prior to injection. Accordingly, the decomposition of the solution and the resulting deposition of its constituents within the solution space may be reduced or prevented, thereby decreasing or precluding the occurrence of a blockage.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional under 35 U.S.C. § 121 of U.S.application Ser. No. 13/722,182, filed Dec. 20, 2012, the entirecontents of which is incorporated herein by reference.

BACKGROUND Field

The present disclosure relates to devices, systems, and methods directedto the injection of solutions into a high-temperature environment.

Description of Related Art

In a nuclear reactor, deposition solutions are often injected into ahigh temperature/pressure feed-water line in order to deposit materialson reactor surfaces. FIG. 1 is a schematic view of a conventionalboiling water nuclear reactor (BWR) including deposition solutioninjection. Referring to FIG. 1, a hydrogen injection system 2 may beused to inject hydrogen into a feed-water suction line 4 b (the suctionline 4 b is the inlet to feed-water pumps 10) to act as an oxygenscavenger for the water circulating in the reactor 8. In conjunctionwith the hydrogen injection system 2, a noble metal (e.g., platinum)deposition solution injection system 6 may be used to inject adeposition solution into the feed-water discharge line 4 a in order todeposit platinum ions on surfaces of the reactor 8. While the reactor 8is depicted as a Boiling Water Reactor (BWR) in FIG. 1, it should beunderstood that other types of nuclear reactors could also make use ofdeposition solution injections (such as the platinum deposition solutiondescribed herein). The platinum deposition solution may be, for example,a platinum salt solution of sodium hexahydroxyplatinate (Na₂Pt(OH)₆). Byinjecting the solution into the feed-water discharge line 4 a, platinumions may deposit onto surfaces of the reactor 8 so that the platinum mayact as a catalyst to react the injected hydrogen with oxygen moleculesthat may be present in the reactor. By causing hydrogen to react withoxygen molecules on surfaces of the reactor 8, water (H₂O) molecules maybe produced. This reaction acts to reduce and potentially eliminateoxygen molecules present on surfaces of the reactor 8 that may otherwisepromote corrosion of metal components, thereby extending the useful lifeof reactor components.

FIG. 2 is a side, cross-sectional view of a conventional depositionsolution injector configuration. Referring to FIG. 2, a conventionaldeposition solution injector configuration 12 may include a chemicalfeed skid 24 supplying a deposition solution to the feed-water dischargeline 4 a. The chemical feed skid 24 typically provides the chemicaldeposition solution at ambient temperatures with a flow-rate of around50-120 cm³/minute and a pressure typically less than 1250 psi (viapositive displacement pumps). A chemical feed line 26 may provide thedeposition solution from the chemical feed skid 24 to the injection tap20. One or more injector valves 14 may be included in the chemical feedline 26 to provide a shutoff for the deposition solution in the chemicalfeed line 26. Typically, a pipe stub 16 is included at the injectorvalve 14 discharge. A weldment 18 may connect the injection tap 20 tothe pipe stub 16 and feed-water discharge line 4 a.

Because a distal end of a conventional injection tap 20 may extend onlyto an inner surface of the feed-water discharge line 4 a, a depositedmaterial 22 may form within the distal end of the injection tap 20. Thedeposited material 22 may form at the injection point, as the ambient(i.e., low) temperature deposition solution is mixed with an intrudingeddy flow of the high temperature, high velocity feed-water (rangingbetween 260 and 420° F. with a flow velocity of about 10-20 ft/sec) thatmay cause the deposition solution to break down into platinum ions whichare then deposited within the inner distal end of the injection tap 20(it is noted that sodium hexahydroxyplatinate, Na₂Pt(OH)₆, begins tobreak down at temperatures of 300-500° C.). Blockage of the injectiontap 20 caused by the deposited material 22 may cause the positivedisplacement pumps to increase injection pressure to provide thespecified injection flow rate. Pressure may increase to the designpressure of the deposition solution injector configuration 12, resultingin termination of an injection before all of the deposition solution isinjected. This may cause a reduced amount of platinum to be depositedwithin the reactor 8, itself. Furthermore, blockage of the injection tap20 may prevent performance of the next scheduled injection (typicallydone once per year), or require an unplanned reactor shutdown to removethe blockage.

In addition to blockage of the injection tap 20 by the depositedmaterial 22 within the injection point, smearing of deposited material22 may also occur along the inner surfaces of the feed-water dischargeline 4 a as the slowly flowing deposition solution is unable to escapethe boundary layer and enter the bulk flow of the feed-water. Thesmearing may cause significant amounts of platinum ions to deposit alongthe inside of the feed-water discharge line 4 a where it is not neededor desired, which may consequently reduce the amount of platinum thatreaches the reactor 8.

SUMMARY

An insulated solution injector may include an outer tube, an inner tubearranged within the outer tube, an inboard end section at a distal endof the outer tube and the inner tube, and an outboard end section at anopposing proximal end of the outer tube and the inner tube. The outertube may have a first outer surface and a first inner surface. The innertube may have a second outer surface and a second inner surface, thefirst inner surface of the outer tube and the second outer surface ofthe inner tube defining an annular space, and the second inner surfaceof the inner tube defining a solution space. The inboard end section mayinclude a base portion and a shield portion projecting from the baseportion, the base portion having a hole extending therethrough, the holebeing in communication with the solution space, and the shield portionhaving a groove extending along a length thereof from the base portion.

An injection system may include a pipe and an insulated solutioninjector penetrating the pipe. The pipe may have an interior surfacedefining a flow space, wherein the inboard end section of the insulatedsolution injector is within the flow space.

A method of injecting a solution into a high temperature liquid streammay include inserting an injector into a pipe configured to carry a flowof the high temperature liquid stream. The injector may be configured todeliver the solution into the high temperature liquid stream. Theinjector may include an outer tube and an inner tube arranged within theouter tube. The outer tube and the inner tube may define an annularspace therebetween. The method may additionally include insulating thesolution from the high temperature liquid stream while the solution isin the injector. The method may also include injecting the solution intothe high temperature liquid stream. The method may further includeshielding the solution from a full velocity of the flow during theinjecting.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the non-limiting embodimentsherein may become more apparent upon review of the detailed descriptionin conjunction with the accompanying drawings. The accompanying drawingsare merely provided for illustrative purposes and should not beinterpreted to limit the scope of the claims. The accompanying drawingsare not to be considered as drawn to scale unless explicitly noted. Forpurposes of clarity, various dimensions of the drawings may have beenexaggerated.

FIG. 1 is a schematic view of a conventional boiling water nuclearreactor (BWR) including deposition solution injection;

FIG. 2 is a side, cross-sectional view of a conventional depositionsolution injector configuration;

FIG. 3 is a side, cross-sectional view of a deposition solution injectorconfiguration according to a non-limiting embodiment;

FIG. 4A is a side, cross-sectional view of a distal end of a depositionsolution injector configuration according to a non-limiting embodiment;

FIG. 4B is a top, cross-sectional view along line A-A of the depositionsolution injector configuration of FIG. 4A;

FIG. 5A is an upper perspective view of an insulated solution injectoraccording to a non-limiting embodiment;

FIG. 5B is a lower perspective view of an insulated solution injectoraccording to a non-limiting embodiment;

FIG. 6 is a side, cross-sectional view of an insulated solution injectoraccording to a non-limiting embodiment;

FIG. 7 is a side, cross-sectional view of an insulated injection systemaccording to a non-limiting embodiment; and

FIG. 8 is a top view along line B-B of the insulated solution injectorof the insulated injection system of FIG. 7.

DETAILED DESCRIPTION

It should be understood that when an element or layer is referred to asbeing “on,” “connected to,” “coupled to,” or “covering” another elementor layer, it may be directly on, connected to, coupled to, or coveringthe other element or layer or intervening elements or layers may bepresent. In contrast, when an element is referred to as being “directlyon,” “directly connected to,” or “directly coupled to” another elementor layer, there are no intervening elements or layers present. Likenumbers refer to like elements throughout the specification. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items.

It should be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers, and/or sections should not be limited by these terms. Theseterms are only used to distinguish one element, component, region,layer, or section from another region, layer, or section. Thus, a firstelement, component, region, layer, or section discussed below could betermed a second element, component, region, layer, or section withoutdeparting from the teachings of example embodiments.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,”“upper,” and the like) may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It should be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” may encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The terminology used herein is for the purpose of describing variousembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“includes,” “including,” “comprises,” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, hut do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of exampleembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, example embodiments should not be construed aslimited to the shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing. Forexample, an implanted region illustrated as a rectangle will, typically,have rounded or curved features and/or a gradient of implantconcentration at its edges rather than a binary change from implanted tonon-implanted region. Likewise, a buried region formed by implantationmay result in some implantation in the region between the buried regionand the surface through which the implantation takes place. Thus, theregions illustrated in the figures are schematic in nature and theirshapes are not intended to illustrate the actual shape of a region of adevice and are not intended to limit the scope of example embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, including those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

FIG. 3 is a side, cross-sectional view of a deposition solution injectorconfiguration according to a non-limiting embodiment. Referring to FIG.3, the deposition solution injector configuration 32 includes a hollowinjector tube 30 with a distal end 30 a that extends beyond the innersurface of the feed-water discharge line 4 a. In particular, the distalend 30 a of the injector tube 30 may extend beyond a determined boundarylayer of the bulk flow of fluids traveling through the feed-waterdischarge line 4 a. The depth of the boundary layer (and, the requiredlength X of the distal end 30 a of the injector tube 30) may varydepending upon the temperature and velocity of the feed-water. The depthof the boundary layer may also vary depending on the type of fluidflowing in the feed-water discharge line 4 a (with potentially varyingviscosity), the diameter and material of the feed-water discharge line 4a, as well as other parameters known to impact the Reynolds number (andresulting boundary layer depth) of fluid flowing in the feed-waterdischarge line 4 a. It should therefore be understood that the length Xshould at least be long enough to extend beyond the boundary layer ofthe fluid flowing in the feed-water discharge line 4 a.

The deposition solution injector configuration 32 also includes a widediameter pipe stub 16 a with an inner diameter that matches or slightlyexceeds the outer diameter of the injector tube 30. The wide diameterpipe stub 16 a provides support to minimize vibration stresses theinjector tube 30 caused by feed-water flow forces.

The inner diameter of the injector tube 30 may also contribute topotential blockage caused by deposited material, if the depositionmaterial is heated to high temperatures (e.g., temperatures at or abovethe decomposition temperature of the deposition material) as it flows tothe distal end 30 a of the injector tube 30. For this reason, the insidediameter of the injector tube 30 should be sized to be sufficientlysmall, ensuring that the deposition solution flows relatively quicklythrough the hot region adjacent to the feed-water discharge line 4 a.For a 50-120 cm³/minute flow rate of deposition solution through theinjector tube 30, a ⅛ inch inner diameter of the injector tube 30 wouldresult in flow velocities of 3-9 inches/second. This would cause thedeposition solution to be in the hot region for less than a second,thereby ensuring that the deposition solution does not degrade duringthis short period.

FIG. 4A is a side, cross-sectional view of a distal end of a depositionsolution injector configuration according to a non-limiting embodiment.Referring to FIG. 4A, the injector tube 30 is provided with an injectionslot 30 b located on a downstream side of the injector tube 30(specifically, the injector slot 30 b is downstream of the feed-waterflow passing across the distal end 30 a of the injector tube 30). Bylocating the injection slot 30 b on the downstream side of the injectortube 30, the injection slot 30 b is somewhat sheltered from the highpressure flow of the feed-water, thereby reducing the potential for theinjector tube 30 to become clogged by deposited material.

The injector tube 30 should be adequately sized to ensure that theentire injection slot 30 b extends beyond the boundary layer of theflowing feed-water, just as the distal end 30 a of the injector tube 30should extend beyond the boundary layer (as described in FIG. 3). Thisensures that the deposition solution may be fully injected into the bulkflow of feed-water in the feed-water discharge line 4 a withoutexperiencing unnecessarily high deposition of platinum ions on theinside of the feed-water discharge line 4 a. For this reason, length Y(the injector tube 30 length from the inner surface of the feed-waterdischarge line 4 a to the opening of the injection slot 30 b) mustextend beyond the boundary layer of the feed-water. As described in FIG.3, the boundary layer depth may vary depending on the temperature andvelocity of the feed-water, the type of fluid flowing in the feed-waterline, the diameter and material of the feed-water line, etc. As anexample, for a 16 inch diameter feed-water discharge line 4 a withflowing water in a range of 15-20 feet/second at a temperature of260-420° F., a length Y of 1 inch is adequate to ensure that the entireinjection slot 30 b extends beyond the boundary layer of the fluidsflowing in the feed-water discharge line 4 a.

The size of the injection slot 30 b itself may also impact the potentialblockage of the injector tube 30. Therefore, the cross-sectional area ofthe injection slot 30 b should be properly sized to ensure that the exitvelocity of the deposition solution approximately matches the feed-waterflow velocity, thereby ensuring that feed-water eddy flows do not enterthe injection slot 30 b and cause deposition and possible blockage.

The injection slot 30 b may be located a distance below the terminus ofthe distal end 30 a of the injector tube 30 to further shelter theinjection slot 30 b from the high pressures of the feed-water flow.However, the distal end 30 a of the injector tube 30 should not extendtoo far beyond the depth of the feed-water boundary layer. By notextending the distal end 30 a of the injector tube 30 too far beyond thelocation of the boundary layer, the risk of bending and damage to theinjector tube 30 by the high velocity feed-water flow may be reduced oravoided. In a non-limiting embodiment, the length X (the full length ofthe distal end 30 a of the injector tube 30 extending within thefeed-water discharge line 4 a) is not more than about 20% greater thanthe required length Y. In another non-limiting embodiment, thedifference between X and Y is not more than one inch.

FIG. 4B is a top, cross-sectional view along line A-A of the depositionsolution injector configuration of FIG. 4A. As discussed in FIG. 4A, theinjection slot 30 b may be located on a downstream side of the injectortube 30 (the downstream side means downstream of the feed-water flowdirection). The axial, cross-sectional profile 30 c of the injector tube30 may be a tapered, oval-shape with two acute ends (as shown in FIG.4B) to hydrodynamically reduce feed-water fluid forces that may beexperienced at the interface between the injection slot 30 b and thebulk flow of the feed-water. The injection slot 30 b may be located onthe downstream-facing acute end of the injector tube 30 (as shown inFIG. 4B). The axial, cross-sectional profile 30 c may also be circular,square, or other suitable shape, so long as the injection slot 30 b islocated on the downstream side of the injector tube 30 to minimize eddyflow of incident feed-water that may enter into the injector tube 30.Furthermore, premature decomposition and deposition of the solution maybe reduced or prevented by hindering the transfer of heat to thesolution during the passage of the solution through the injector to thefeed-water. Such hindering of the transfer of heat may be achieved withan insulated solution injector.

FIG. 5A is an upper perspective view of an insulated solution injectoraccording to a non-limiting embodiment. FIG. 5B is a lower perspectiveview of an insulated solution injector according to a non-limitingembodiment. FIG. 6 is a side, cross-sectional view of an insulatedsolution injector according to a non-limiting embodiment. Referring toFIGS. 5A-5B and 6, the insulated solution injector 100 includes anarrangement of an inner tube 104 within an outer tube 102. The outertube 102 has a first outer surface 102 a and a first inner surface 102b. The inner tube 104 has a second outer surface 104 a and a secondinner surface 104 b.

The second outer surface 104 a of the inner tube 104 is spaced apartfrom the first inner surface 102 b of the outer tube 102. As a result,the first inner surface 102 b of the outer tube 102 and the second outersurface 104 a of the inner tube 104 define an annular space 103. Aninsulating layer may occupy the annular space 103 between the outer tube102 and the inner tube 104. The insulating layer may be a gas layer. Theinner tube 104 may be concentrically arranged within the outer tube 102.The second inner surface 104 b of the inner tube 104 defines a solutionspace 105. The annular space 103 is isolated from the solution space105.

An inboard end section 106 is at a distal end of the outer tube 102 andthe inner tube 104. The inboard end section 106 includes a base portion106 a and a shield portion 106 b projecting from the base portion 106 a.The base portion 106 a has a hole 106 c extending therethrough. The hole106 c is in communication with the solution space 105. The hole 106 cextending through the base portion 106 a may have a diameter rangingfrom 0.1 to 0.3 inches. The shield portion 106 b has a groove 106 dextending along a length thereof from the base portion 106 a. The groove106 d may be V-shaped and extend along an entire length of the shieldportion 106 b such that the inboard end section 106 has a “pac-man”shape based on a plan view. In such a case, the groove 106 d of theshield portion 106 b exposes a wedge-shaped area of the base portion 106a. The hole 106 c extends through the wedge-shaped area of the baseportion 106 a. In another non-limiting embodiment, the groove 106 d maybe U-shaped or another suitable shape. A portion or more of the side ofthe shield portion 106 b opposite to the groove 106 d may be slanted orinclined. Additionally, the terminus of the shield portion 106 b may beleveled.

An outboard end section 108 is at an opposing proximal end of the outertube 102 and the inner tube 104 relative to the inboard end section 106.The outboard end section 108 may have an opening configured to allowatmospheric air to enter and circulate within the annular space 103 bynatural convection. For instance, the insulated solution injector 100may be installed such that the outboard end section 108 points upward toallow the higher temperature air circulating in the annular space 103 toescape by natural convection. Alternatively, the annular space 103 maybe sealed, wherein the annular space 103 is filled with a gas layer orrendered as a vacuum.

Although the insulated solution injector 100 is shown in the drawings asbeing in a linear form, it should be understood that example embodimentsare not limited thereto. For instance, the insulated solution injector100 may alternatively be in a curved form. As an example of a curvedform, the insulated solution injector 100 may have an inboard endsection 106 that is straight to facilitate insertion into a pipe (e.g.,feed-water pipe), while the outboard end section 108 may be curved toaccommodate a particular configuration (and/or to maneuver around anadjacent structure), vice versa, or both curved based on situationalneeds.

FIG. 7 is a side, cross-sectional view of an insulated injection systemaccording to a non-limiting embodiment. FIG. 8 is a top view along lineB-B of the insulated solution injector of the insulated injection systemof FIG. 7. Referring to FIGS. 7-8, an injection system 400 includes apipe 402 having an exterior surface 402 a and an interior surface 402 b.The pipe 402 may be a feed-water pipe. The interior surface 402 b of thepipe 402 defines a flow space therein for a liquid stream (e.g.,feed-water). An insulated solution injector 100 penetrates the pipe 402.Although the insulated solution injector 100 is shown in the drawings aspenetrating an underside of the pipe 402, it should be understood thatexample embodiments are not limited thereto. For instance, the insulatedsolution injector 100 may alternatively penetrate an upper-side ortop-side of the pipe 402. With an upper-side or top-side penetration ofthe pipe 402, the air that is being heated in the annular space 103 bythe pipe 402 and/or the liquid stream can escape relatively easily bynatural convection.

The insulated solution injector 100 may be as described in connectionwith FIGS. 5A-5B and 6. In particular, the insulated solution injector100 includes an outer tube 102 having a first outer surface 102 a and afirst inner surface 102 b. An inner tube 104 is arranged within theouter tube 102. The inner tube 104 having a second outer surface 104 aand a second inner surface 104 b. The first inner surface 102 b of theouter tube 102 and the second outer surface 104 a of the inner tube 104define an annular space 103. The second inner surface 104 b of the innertube 104 defines a solution space 105.

An inboard end section 106 is at a distal end of the outer tube 102 andthe inner tube 104. The inboard end section 106 is arranged so as to bewithin the flow space of the pipe 402. The inboard end section 106includes a base portion 106 a and a shield portion 106 b projecting fromthe base portion 106 a. The base portion 106 a has a hole 106 cextending therethrough. The flow space of the pipe 402 is incommunication with the solution space 105 via the hole 106 c. The shieldportion 106 b has a groove 106 d extending along a length thereof fromthe base portion 106 a. An outboard end section 108 is at an opposingproximal end of the outer tube 102 and the inner tube 104 relative tothe inboard end section 106.

The insulated solution injector 100 may extend into the pipe 402 about 5to 15% of an inside diameter of the pipe 402. For instance, theinsulated solution injector 100 may extend into the pipe 402 about 1 to2 inches beyond the interior surface 402 b of the pipe 402.

A method of injecting a solution 406 into a high temperature liquidstream 404 includes inserting an injector 100 into a pipe 402 configuredto carry a flow of the high temperature liquid stream 404. The injector100 is configured to deliver the solution 406 into the high temperatureliquid stream 404. The injector 100 includes an outer tube 102 and aninner tube 104 arranged within the outer tube 102. The outer tube 102and the inner tube 104 define an annular space 103 therebetween. Themethod additionally includes insulating the solution 406 from the hightemperature liquid stream 404 while the solution 406 is in the injector100. The method also includes injecting the solution 406 into the hightemperature liquid stream 404 while insulating the solution 406 stillwithin the injector 100. The method further includes shielding thesolution 406 from a full velocity of the flow during the injecting.

The inserting may include positioning the injector 100 to facilitatedelivery of the solution 406 beyond the boundary layer of the flow ofthe high temperature liquid stream 404. The high temperature liquidstream 404 may be a high temperature water stream (e.g., feed-waterstream).

The insulating may include providing a gas or a vacuum in the annularspace 103. For instance, the insulating may include providing air (e.g.,atmospheric as the gas in the annular space 103. The air in the annularspace 103 may circulate by natural convention such that the warmerinternal air exits while the cooler external air enters the annularspace 103. As a result, the solution 406 in the solution space 105 isrelatively insulated from the high temperature environment of the pipe402 and its contents as the solution 406 travels from the outboard endsection 108 to the inboard end section 106 where the solution 406 isinjected into the high temperature liquid stream 404.

The injecting may include delivering a noble metal precursor as thesolution 406 into the high temperature liquid stream 404. In anon-limiting embodiment, the injecting may include delivering a platinumprecursor into the high temperature liquid stream 404. For instance, theinjecting may include delivering sodium hexahydroxyplatinate(Na₂Pt(OH)₆) into the high temperature liquid stream 404.

In view of the insulated solution injector, the injection system, andthe method of injecting herein, the solution may be kept to atemperature below its decomposition temperature while the solution iswithin the injector. Accordingly, the decomposition of the solution(e.g., Na₂Pt(OH)₆) and the resulting deposition of its constituents(e.g., Pt) within the injector may be reduced or prevented, therebydecreasing or precluding the occurrence of a blockage.

While a number of example embodiments have been disclosed herein, itshould be understood that other variations may be possible. Suchvariations are not to be regarded as a departure from the spirit andscope of the present disclosure, and all such modifications as would beobvious to one skilled in the art are intended to be included within thescope of the following claims.

The invention claimed is:
 1. A method of injecting a solution into ahigh temperature liquid stream, the method comprising: inserting aninjector into a pipe configured to carry a flow of the high temperatureliquid stream, the injector configured to deliver the solution into thehigh temperature liquid stream, the injector including an outer tube andan inner tube arranged within the outer tube, the outer tube and theinner tube defining an annular space therebetween; insulating thesolution from the high temperature liquid stream while the solution isin the injector; injecting the solution into the high temperature liquidstream; and shielding the solution from a full velocity of the flowduring the injecting, the shielding occurring on an upstream side of theinjector relative to the flow after the solution has been injected intothe high temperature liquid stream.
 2. The method of claim 1, whereinthe inserting includes positioning the injector to facilitate deliveryof the solution beyond a boundary layer of the flow of the hightemperature liquid stream.
 3. The method of claim 1, wherein theinsulating includes providing a gas or a vacuum in the annular space. 4.The method of claim 3, wherein the insulating includes providing air inthe annular space.
 5. The method of claim 1, wherein the injectingincludes delivering a noble metal precursor into the high temperatureliquid stream.
 6. The method of claim 5, wherein the injecting includesdelivering a platinum precursor into the high temperature liquid stream.7. The method of claim 6, wherein the injecting includes deliveringsodium hexahydroxyplatinate (Na₂Pt(OH)₆) into the high temperatureliquid stream.
 8. The method of claim 1, wherein the injecting includesdelivering the solution into a high temperature water stream.